Electronic devices (e.g., mobile phones, media players, electronic watches, and the like) operate when there is charge stored in their batteries. Batteries charge when the electronic device is coupled to a power source, such as via a charging cord. Using charging cords to charge batteries in electronic devices, however, requires the electronic device to be physically tethered to a power outlet. In areas where there are many devices that are charging, there may be a large, disorganized grouping of cables that could easily get tangled. Additionally, using charging cords requires the mobile device to have a receptacle configured to mate with the charging cord. The receptacle is typically a cavity in the electronic device that provides avenues within which dust and moisture can intrude and damage the device. Furthermore, a user of the electronic device has to physically connect the charging cable to the receptacle in order to charge the battery.
To avoid such shortcomings, wireless charging stations have been developed to wirelessly charge electronic devices. Electronic devices may charge by merely resting on a charging surface of the charging station. Magnetic fields generated by transmitters disposed below the charging surface may induce corresponding currents in receivers that have a corresponding inductive coil. The induced currents may be used by the electronic device to charge an internal battery.
Existing wireless charging systems have a number of disadvantages. For instance, wireless charging surfaces require a specific charging region disposed on top of a transmitter coil embedded beneath the surface. This requires the electronic device to be placed in a very specific area on the charging surface. If an electronic device is placed outside of the charging region, the electronic device may not wirelessly charge due to the absence of a magnetic field. Additionally, since single axis magnetic fields require transmitter and receiver coils to be disposed on parallel planes, the electronic device must be positioned in a particular orientation (e.g., with the back face of the device resting on the surface) in order for charging to occur.